isisd/isis_csm.c

   1 /*
   2  * IS-IS Rout(e)ing protocol - isis_csm.c
   3  *                             IS-IS circuit state machine
   4  * Copyright (C) 2001,2002    Sampo Saaristo
   5  *                            Tampere University of Technology
   6  *                            Institute of Communications Engineering
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public Licenseas published by the Free
  10  * Software Foundation; either version 2 of the License, or (at your option)
  11  * any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  16  * more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along
  19  * with this program; see the file COPYING; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include <zebra.h>
  24
  25 #include "log.h"
  26 #include "memory.h"
  27 #include "if.h"
  28 #include "linklist.h"
  29 #include "command.h"
  30 #include "thread.h"
  31 #include "hash.h"
  32 #include "prefix.h"
  33 #include "stream.h"
  34
  35 #include "isisd/isis_constants.h"
  36 #include "isisd/isis_common.h"
  37 #include "isisd/isis_flags.h"
  38 #include "isisd/isis_circuit.h"
  39 #include "isisd/isis_lsp.h"
  40 #include "isisd/isis_pdu.h"
  41 #include "isisd/isis_network.h"
  42 #include "isisd/isis_misc.h"
  43 #include "isisd/isis_constants.h"
  44 #include "isisd/isis_adjacency.h"
  45 #include "isisd/isis_dr.h"
  46 #include "isisd/isisd.h"
  47 #include "isisd/isis_csm.h"
  48 #include "isisd/isis_events.h"
  49 #include "isisd/isis_errors.h"
  50
  51 static const char *const csm_statestr[] = {"C_STATE_NA", "C_STATE_INIT",
  52                                      "C_STATE_CONF", "C_STATE_UP"};
  53
  54 #define STATE2STR(S) csm_statestr[S]
  55
  56 static const char *const csm_eventstr[] = {
  57         "NO_STATE",     "ISIS_ENABLE",    "IF_UP_FROM_Z",
  58         "ISIS_DISABLE", "IF_DOWN_FROM_Z",
  59 };
  60
  61 #define EVENT2STR(E) csm_eventstr[E]
  62
  63 struct isis_circuit *
  64 isis_csm_state_change(int event, struct isis_circuit *circuit, void *arg)
  65 {
  66         int old_state;
  67         struct isis *isis = NULL;
  68
  69         old_state = circuit ? circuit->state : C_STATE_NA;
  70         if (IS_DEBUG_EVENTS)
  71                 zlog_debug("CSM_EVENT: %s", EVENT2STR(event));
  72
  73         switch (old_state) {
  74         case C_STATE_NA:
  75                 if (circuit)
  76                         zlog_warn("Non-null circuit while state C_STATE_NA");
  77                 assert(circuit == NULL);
  78                 switch (event) {
  79                 case ISIS_ENABLE:
  80                         circuit = isis_circuit_new();
  81                         isis_circuit_configure(circuit,
  82                                                (struct isis_area *)arg);
  83                         circuit->state = C_STATE_CONF;
  84                         break;
  85                 case IF_UP_FROM_Z:
  86                         isis = isis_lookup_by_vrfid(((struct interface *)arg)->vrf_id);
  87                         if (isis == NULL) {
  88                                 zlog_warn(
  89                                         " %s : ISIS routing instance not found",
  90                                         __func__);
  91                                 break;
  92                         }
  93                         circuit = isis_circuit_new();
  94                         isis_circuit_if_add(circuit, (struct interface *)arg);
  95                         listnode_add(isis->init_circ_list, circuit);
  96                         circuit->isis = isis;
  97                         circuit->state = C_STATE_INIT;
  98                         break;
  99                 case ISIS_DISABLE:
 100                         zlog_warn("circuit already disabled");
 101                         break;
 102                 case IF_DOWN_FROM_Z:
 103                         zlog_warn("circuit already disconnected");
 104                         break;
 105                 }
 106                 break;
 107         case C_STATE_INIT:
 108                 assert(circuit);
 109                 switch (event) {
 110                 case ISIS_ENABLE:
 111                         isis_circuit_configure(circuit,
 112                                                (struct isis_area *)arg);
 113                         if (isis_circuit_up(circuit) != ISIS_OK) {
 114                                 isis_circuit_deconfigure(
 115                                         circuit, (struct isis_area *)arg);
 116                                 break;
 117                         }
 118                         circuit->state = C_STATE_UP;
 119                         isis_event_circuit_state_change(circuit, circuit->area,
 120                                                         1);
 121                         listnode_delete(circuit->isis->init_circ_list,
 122                                         circuit);
 123                         break;
 124                 case IF_UP_FROM_Z:
 125                         assert(circuit);
 126                         zlog_warn("circuit already connected");
 127                         break;
 128                 case ISIS_DISABLE:
 129                         zlog_warn("circuit already disabled");
 130                         break;
 131                 case IF_DOWN_FROM_Z:
 132                         isis_circuit_if_del(circuit, (struct interface *)arg);
 133                         listnode_delete(circuit->isis->init_circ_list,
 134                                         circuit);
 135                         isis_circuit_del(circuit);
 136                         circuit = NULL;
 137                         break;
 138                 }
 139                 break;
 140         case C_STATE_CONF:
 141                 assert(circuit);
 142                 switch (event) {
 143                 case ISIS_ENABLE:
 144                         zlog_warn("circuit already enabled");
 145                         break;
 146                 case IF_UP_FROM_Z:
 147                         isis_circuit_if_add(circuit, (struct interface *)arg);
 148                         if (isis_circuit_up(circuit) != ISIS_OK) {
 149                                 isis_circuit_if_del(circuit, (struct interface *)arg);
 150                                 flog_err(
 151                                         EC_ISIS_CONFIG,
 152                                         "Could not bring up %s because of invalid config.",
 153                                         circuit->interface->name);
 154                                 break;
 155                         }
 156                         circuit->state = C_STATE_UP;
 157                         isis_event_circuit_state_change(circuit, circuit->area,
 158                                                         1);
 159                         break;
 160                 case ISIS_DISABLE:
 161                         isis_circuit_deconfigure(circuit,
 162                                                  (struct isis_area *)arg);
 163                         isis_circuit_del(circuit);
 164                         circuit = NULL;
 165                         break;
 166                 case IF_DOWN_FROM_Z:
 167                         zlog_warn("circuit already disconnected");
 168                         break;
 169                 }
 170                 break;
 171         case C_STATE_UP:
 172                 assert(circuit);
 173                 switch (event) {
 174                 case ISIS_ENABLE:
 175                         zlog_warn("circuit already configured");
 176                         break;
 177                 case IF_UP_FROM_Z:
 178                         zlog_warn("circuit already connected");
 179                         break;
 180                 case ISIS_DISABLE:
 181                         isis = circuit->area->isis;
 182                         isis_circuit_down(circuit);
 183                         isis_circuit_deconfigure(circuit,
 184                                                  (struct isis_area *)arg);
 185                         circuit->state = C_STATE_INIT;
 186                         isis_event_circuit_state_change(
 187                                 circuit, (struct isis_area *)arg, 0);
 188                         listnode_add(isis->init_circ_list, circuit);
 189                         circuit->isis = isis;
 190                         break;
 191                 case IF_DOWN_FROM_Z:
 192                         isis_circuit_down(circuit);
 193                         isis_circuit_if_del(circuit, (struct interface *)arg);
 194                         circuit->state = C_STATE_CONF;
 195                         isis_event_circuit_state_change(circuit, circuit->area,
 196                                                         0);
 197                         break;
 198                 }
 199                 break;
 200
 201         default:
 202                 zlog_warn("Invalid circuit state %d", old_state);
 203         }
 204
 205         if (IS_DEBUG_EVENTS)
 206                 zlog_debug("CSM_STATE_CHANGE: %s -> %s ", STATE2STR(old_state),
 207                            circuit ? STATE2STR(circuit->state)
 208                                    : STATE2STR(C_STATE_NA));
 209
 210         return circuit;
 211 }